<!DOCTYPE html>
<html class="test-wait">
<head>
<link rel="author" title="Daniel Holbert" href="mailto:dholbert@mozilla.com">
<link rel="help" href="https://bugzilla.mozilla.org/show_bug.cgi?id=1267079">
<style>

@keyframes a {
    0% {
        border-radius: 1px;
    }
}

div {
    animation-name: a;
    animation-duration: 3s;
}

</style>
<script>

function addSheet(text)
{
    var sheet = document.createElement("style");
    sheet.appendChild(document.createTextNode(text));
    document.head.appendChild(sheet);
}

function boom()
{
    requestAnimationFrame(() => { requestAnimationFrame(() => {
        addSheet("div:after { content: 'Z'; }");
        document.documentElement.classList.remove("test-wait");
    }); });
}

window.addEventListener("load", boom, false);

</script>
</head>

<body><div></div></body>
</html>
